1. Technical Field
The present invention is related to a method and apparatus for color adjustment of a display screen in a color display device. In particular, it is related to a method and apparatus for color adjustment of a display screen which provides an interactive user interface which allows users to perform efficiently and effectively a variety of color adjustments, such as a tint adjustment, a white point adjustment, a blue shift adjustment of achromatic colors or the like in the color display device.
2. Prior Art
In the color display devices, such as LCD (Liquid Crystal Display) and CRT, it is ideal that their colors which can be potentially represented are as close as possible to natural colors (Display Color Fidelity). Furthermore, it is also highly desirable to adjust colors automatically with the device or manually by the user in response to the environment in which the device is placed, such as illumination, so that the most suitable color for the respective environment may be displayed (Color Calibration), and to allow the same color to be displayed independently of the color display device which outputs it (Device Transfer Characteristics), etc. These processes are generically referred to as a color management, and it is an important field a variety of researches and developments of which are conducted as an essential item for the coming and subsequent generations of the color display devices (especially of high performance types). For example, the white point adjustment is an item which is previously recognized to be important, and actually provided in color monitors, etc.
And also, it can be said that the color adjustments, such as a tint control between R and G (from reddish yellow to greenish yellow) as is usual with color TVs, etc., and an adjustment of the color density (from the perfect monochrome to the most dense color), are less important than the white point adjustment in the color monitors of office users, etc., but are still essential items for color adjustment in TV, etc.
When these color adjustments are performed by the user using the color display device, it is important that the adjustments are easy for the user to sensately understand, and effective. Current color monitors and color TVs, etc. satisfy this requirement in a way. That is, if they are provided with an adjusting knob, it has a marking on it so that user may confirm how far the knob is turned (physically) to the right or left from the unadjusted position. Or if the adjustment is performed by means of two switches indicating up and down, and left and right, respectively, with an arrow, a pop-up display representing the current adjustment value with a relative position appears on the screen, and since the position representing the adjustment value on the pop-up display changes in response to user pressing one of the switches, the user can confirm the result of the adjustment. And at this moment, the effect of the adjustment is immediately reflected throughout the entire display screen. This means that the color signals converted by the color adjustment are transmitted to the CRT or the LCD panel, the display section, as they are.
In fact, as mentioned above, the method in which the effect of the color adjustment appears interactively on the display screen in response to the color adjustment, and the user continues to adjust the colors while seeing the changes of the displayed colors, is suited for human senses to some extent. But there is an adaptation (habituation) in the human eye. For example, the case of a tint adjustment (a hue adjustment) is referred to as follows. The tint adjustment is a remnant of the beginning of the appearance of the color TV when the dispersion of the displayed color characteristics between receivers was large, but presently, viewers especially sensitive to a color of a face of a person prefer to utilize this adjustment. Here, assume that a color of a face in one display looks too reddish for a user, and he adjusts the tint toward the green (G) side. In this case, he may have his eyes habituated during the adjustment, and not be aware that he has adjusted the color excessively toward the green (G) side, so that he may feel that the color is too greenish when he sees the display screen under the fixed adjustment value again at a later date. The same may occur in the cases of the white point adjustment and blue shift adjustment of achromatic colors.
These problems are considered to arise due to the lack of a color image to be referenced when adjusting the colors. To avoid these problems, the color adjustment may be performed while referring to a color image whose colors are not adjusted at all. To this end, however, there was a problem that it is necessary to have an environment in which the color adjustment is performed with two color display devices of the same type placed side by side, one used to display a color image whose colors are not adjusted, and the other used to display a color image whose colors are adjusted.
The object of the present invention is to overcome the above-mentioned problems, and to provide a method and apparatus for color adjustment of a display screen which provides an interactive user interface which allows users to perform color adjustment efficiently and effectively.
The present invention is related to a method for color adjustment of the display screen in the color display device, such as LCD and CRT. The color adjustment is performed by displaying a color image without any color adjustment at a certain portion of the display screen, displaying a color image with a color adjustment at another portion of the display screen, and referring to the color image without any color adjustment.
According to the present invention mentioned above, an interactive user interface which allows users to perform color adjustment efficiently and effectively may be provided by enabling to display the color image under the color adjustment values at that moment, and simultaneously to display in another area on the same display screen a color image whose colors are not adjusted at all, when performing a variety of color adjustments.
In a preferred example of the method for color adjustment of the display screen according to the present invention, the color adjustment is any one of a tint adjustment, a white point adjustment, or a blue shift adjustment of achromatic colors. The display screen is substantially equally divided into top and bottom parts, or into left and right parts, the color image whose colors are not adjusted at all is displayed on one part of the display screen, and simultaneously the color image whose colors are adjusted is displayed on the other part of the display screen. Alternatively, the display screen is divided into multiple display screens, the color image whose colors are not adjusted at all is displayed on one display screen, and simultaneously the color images whose colors are differently adjusted are displayed on the other display screens, respectively. Furthermore, the configuration is adapted to change the colors of the color image whose colors are adjusted, in real time in response to the color adjusting operation by the user. In either case, the present invention may be embodied more efficiently and effectively.
And, the apparatus for color adjustment of the display screen according to the present invention addresses an apparatus for color adjustment in which the color adjustment is performed by means of a block (hereinafter called xe2x80x9ca color adjustment blockxe2x80x9d) for delaying by a certain clock cycle (Dca cycle) the digital color data which are synchronized with the pixel clock and successively inputted into it, transforming them, and outputting them in a pipeline manner. In this apparatus for color adjustment, a counter which allows the apparatus to recognize in which row and column within one frame an input color image signal is to be displayed is provided by monitoring and counting synchronous input signals, such as horizontal synchronous signals (HSYNCH) or vertical synchronous signals (VSYNCH), and during a color adjustment period, the counter values are utilized (1) to pass input color signals used to display an area in the display screen through the color adjustment block, and transmit the color signals delayed by the Dca cycle and transformed in the color adjustment block to the later display section, and (2) not to pass input color signals used to display another area in the display screen through the color adjustment block, only delay them by the Dca cycle, and transmit them to the later display section, so that the color image whose colors are adjusted is displayed at a certain portion of the display screen, and the color image whose colors are not adjusted at all is displayed at another portion of the display screen.
According to the apparatus for color adjustment of the present invention as described above, the method for color adjustment of the display screen of the present invention may be implemented by adding a relatively simple configuration. In a preferred example of the apparatus for color adjustment according to the present invention, the switching between the signals of said cases (1) and (2) is performed by MUXs (multiplexers) utilizing said counter values. And at the end of the color adjustment period, the selections of the MUXs are fixed so that the color signals having passed the color adjustment block are transmitted to the display section of the later stage over the whole display area. In either case, the apparatus for color adjustment according to the present invention may be more favorably implemented.